Dry dock



March 25 1924. 1,487,742

M. F. HILL DRY DOCK Filed March 2'? 1919 ma@ m pulled by the chains overthe center so that the float rests against the wharf 5 and may be in amore secure position after which any suitable ram or may be used to pushit back lor the center and downward again, when it is desired to lowerthe dock to re lease the ship. Upon the outriggers 19 any suitableflooring or grating 32 may be laid either permanently or temporarily forthe convenience 'of workmrin around the hull. vUpon the ends of theoutriggers may be mounted sockets into which telegraph poles or othersuitable devices 34; may be inserted and fastened, which, as indicatedin broken lines, may be of suoli length as to reach above the waterlevel to show the po siti'on ol the dock when submerged and to ward oliany craft that might collide with the same. 'lhe motor shatt ot themotor Il() should be provided with a thrust bea-ring 2.3 to talre thepull oit' the worm gear mechanism 36 employed to rotate the shalt 31 andthe thrust bearing should be strongly anclrored to the foundations inany suitable way.

In F ig. 3 is shown the preferred form of trestle 12 consisting ofgirders 3T and between which are connected hollow columns 39. Thegirders 3T are linked by the pivots l1 to the bottom oic the float andby tl e pivots all to the foundations 8 or to the caps t3 of thefoundations. By this means the columns 39 and girders 87 and 3S Jtorni along rigid girder with a plurality oi' 'lfoundations S so that in caseany one foundation should prove insecure, other Jfoundations will assumea portion of its load. Furthermore if there is a tendency ot thefoundations to sink, they will all sink more or less in unison owing tothe distribution ot the load.

As many motors 30 and worm gear drives 36 may be used as may be desiredto operate the shaft 31. The shaft 31 should be sut'- iciently strong toequalize the pull oit the chains 22. Each, chain may be located in linewith a transverse stitlener 4:6, located across the inside ot' thefloat, each stitlener in alignment with an Outrigger 19. The lloat maybe provided with a central longitudinal girder 44C to transmit the loadtrom the blocks 28 under the ships keel to the trestle 12. The crosssection ol this link is shown in F ig. 4, the column 39 being hollow andthe girders 37 and 38 being supplied lwith stitleners 45 over and underthe columns for the purpose of transmitting the load of the ship down tothe foundations. The interior of the float may be provided with anysuitable ship construction such for example as the transverse or thelongitudinal system, with the main transverses over the columns 39 asindicated by the brokenA lines 46 and with any suitable longitudinalstilleners located Wherever there is a water i erf/42 pressure to besustained and ol suliicient strength to withstai'id the water pressureat any depth to which the float may be submerged. 'lhe buoyancy in thecolumns 39 and in the wooden posts 3% may be so ad `iusted as tomaintain the specilic gravity o whole structure somewhat greater thanits displacement or water at all levels so that the whole constructionhas a tendency to sink when permitted to do so and yet such acomparatively small tendency that little power is required to raise itto the water level. Upon the wharf 7 may be mounted any suitablescallolding i'or permanent purposes. Upon the water side ot' the hullthe scall'olding may be nailed to or otherwise supported upon thetelegraph poles 3l; or scaiiolding may be otherwise located and beremovable when desired.

rlhe details ol the preferable hauling mechanism are shown in VFig. 5,the bearings for the counter shalty gears and drum, as well as theanchorages for them, being omitted. A series of motors l? operatepinions 48 meshing with gears e9 mounted on a countershaft 50, operatingnorms 51 on the shaft, which in turn rotate worin gears 52 and worms 53,meshing with worm gears 54 on the chain 'inding drums This constructionpe 1mits the use of a small shaft tor linking the hauling drumstogether, instead ot' the massive shalt required by the tiagramconstruction shown in Figs. 1 and 2, the latter form being shown forillustrating the broad idea. rlhe motors are preterably operated from acommon circuit in multiple with each other, with a common switch andrheostat lor opening and closing the circuit.

Individual motor rheostats may be inserted in the multiple motorcircuits to adjust the current in the dillerent motors to the particularloads they carry.

It' the motors run at 1000 R. P. M. and the pinion spur gear is 1 to Ll,the two worm gears 1 to 25, and the drum 2 ft. in diameter a ship afterbeing located on the blocks may be raised in 15 to 20 minutes. A1440 ft.dock with columns 10 to 12 llt. apart lengthwise, and properlyconstructed is capable of lifting a 12000 ton ship in this short time.

The lifting devices and 24 keep the platform 17 in substantial alignmentthroughout its length.

Any variation in the pulling etlect of shaft 50 is due to its elasticityand the torsional lag of one portion in relation to another4 isminimized by the 'lact that even a torsional twist of the shaft or"1800, which can hardly ever happen, would have an imperceptible etl'ecton the platform. due to the slow speed of the gear. rThe elasticity ofthe platform and of a ship mounted thereon would compensate for anyminute variation in relative rotation ot the drums.

The dock may be as wide and as long as may be desired but the width ofthe float platform may be limited whereY desired to the spacing of theside series of blocks E29. Any variations may be made in the details andform of apparatus 0r in the mechanical movements necessary for liftingthe ship ont of water. The chief requirements of it are that it shall belifted sidewise and upwards by a plurality of lifting mechanismsdistributed alone' the length of the ship thereby dividing up the powerinto compara-tively small units.

that I claim and desire to secure by Letters Patents is:

l. The combination with a ship lifting platform, of a rigid girderdisposed `longitudinally under the keel of a ship carried thereby, a rowof pivotal columns support` ing substantially the ent-ire weight of theship on said girder, a plurality of tension members secured to thegirder for raising and lowering the same, and means for mechanicallyinterconnecting said tension members to simultaneously control the same.

2. A stationary platform, a movable platform alongside the stationaryplatform for lifting a ship sidewise out of the water, supportingcolumns for swinging the movable platform toward and from and at rightangles to the adjacent edge of the stationary platform and to the keelof a ship carried by the movable platform, and means alongside saidmovable platform to maintain the same in a horizontal plane, said lastmentioned means comprising a plurality of auxiliary colunms arrangedalong the outside of said platform and adapted to swing transversely toa ship contained on the platform.

The combination with a boat lifting platform, of a foundation therefor,a supporting column pivotally secured adjacent one end to the platformand pivotally attached adjacent its other end to the foundation, saidplatform being raised and lowered by movement about said foundation` arelatively stationary wharf or-abutment located near and above saidfoundation and against which the plat-form is adapted to rest when movedslightly to one side of the pivotal attachment between the column andthe foundation.

4. A movable platform, a shaft journaled in fixed bearings along oneside of the platform and provided with a series of worms, a series ofworm gears, in mesh with said worms to rotate at a reduced speed, andmeans operatively connecting the worm gears with said platform.

5. A moving platform, a shaft alongside said platform, a plurality ofdriving means geared transversely of said shaft, a series of speedreducing gears transversely of said shaft, and means operativelyconnecting the platform with said speed reducing means.

6. A movable platform, a shaft journaled in fixed bearings alongside themajor dimensions of said platform and provided with a series of worms, aseries of worm gears in mesh with said worms. to run ata reduced speed,said worm gears provided with worm shafts, a series of worm gears inmesh with said series of worm shaft-s to run at a lower speed than saidworm shafts, and means operatively connecting said platform with saidlast mentioned gears.

7. A movable platform, a series of power driven gears, a shaft journaledin xed bearing alongside the platform, a shaft provided with a series ofgears in mesh with the power driven gears and with a series of worms, aseries of worm gears in mesh with said worm to run at a reduced speed,said' worm gears provided with worm shafts, a series of worm gears inmesh with said series of worm shafts, to run at a lower speed than saidworm shafts and means operatively connecting said platform with saidlast mentioned gears.

In testimony whereof, l have affixed my signature to this specification.

MYRON F. HILL.

